The present invention relates to an ink jet recording device, and more particularly, to a tube connection type ink jet recording device in which an ink is supplied from an external ink tank to an ink ejection head through a tube.
In a conventional tube connection type ink jet recording device, an ink tank accumulating therein an ink is fluidly connected by a tube to an ink ejection head from which an ink is ejected toward an image recording medium to form an inked image. FIG. 5 shows the conventional tube connection type ink jet recording device in which two ink ejection heads 1 are connected to first ink supply tube 2 and a second ink supply tube 3 by way of a joint member 4. In FIG. 5, only one ink ejection head 1 is shown. The other ink ejection head is juxtaposed along the ink ejection head 1 in a thickness direction of the drawing sheet. These ink ejection heads 1 are held by a head holder 15.
The joint member 4 includes an outer member 5 and a separate inner member 6 those formed of a resin. The outer member 5 includes a first outer side connecting portion 7 and a second outer side connecting portion 8 provided integrally therewith. The inner member 6 includes a first inner side connecting portion 10, a second inner side connecting portion 12 and outermost two leg portions 16 those provided integrally with each other.
A filter 17 is interposed between the first outer side connecting portion 7 and the first inner side connecting portion 10, and another filter 17 is interposed between the second outer side connecting portion 8 and the second inner side connecting portion 12. While maintaining this state, the first outer and inner side connecting portions 7 and 10 and the second outer and inner side connecting portions 8 and 12 are subjected to ultrasonic melt-bonding for joining the outer and inner members 5 and 6 together.
A first ink supply tube 2 is connected to the first outer side connecting portion 7, and a second ink supply tube 3 is connected to the second outer side connecting portion 8. Further, one of the ink ejection heads 1 has a first ink supply port 13 to which one end of a first ink supply conduit 9 is connected. The first ink supply conduit 9 has another end connected to the first inner side connecting portion 10.
Remaining ink ejection head 1 has a second ink supply port 14 to which one end of a second ink supply conduit 11 is connected. The second ink supply conduit 11 has another end connected to the second inner side connecting portion 12. With such a connecting condition, the leg portions 16 of the inner member 6 is fixed to the head holder 15 by means of screws 18. Thus, the assembly of the ink jet recording device is completed.
With such an arrangement, severe dimensional accuracy of the outer and inner members 5 and 6 must be required, otherwise insufficient jointing occurs between the outer and the inner members 5 and 6, and one of the members 5 or 6 may be easily peeled off from the remaining member 6 or 5. To be more specific, upon ultrassonic melt-bonding between the first outer and inner side connecting portions 7 and 10 and between the second outer and inner side connecting portions 8 and 12 after positional alignment between the portions 7 and 10 and between the portions 8 and 12 to provide joint portions between the members 7 and 10 and between the members 8 and 12, tensile force or compressive force may be generated between the joint portions, if a distance between the first and second outer side connecting portions 7 and 8 of the outer member 5 and a distance between the first and second inner side connecting portions 10 and 12 of the inner member 6 are not accurately provided. Further, due to the application of tensile force or compressive force to the joint portions, filters 17 at the joint portions may be damaged.
It is an object of the present invention to overcome the above-described problem and to provide an ink jet recording device capable of facilitating and ensuring assembly particularly of the joint portions serving as a coupling of a plurality of ink passages.
Another object of the present invention is to provide such ink jet recording device having a simple construction, yet providing complete assembly between inner and outer members without any peeling off therebetween with lesser influence of dimensional inaccuracy of the inner and outer members.
These and other objects of the present invention will be attained by an ink jet recording device having a joint portion where a plurality of fluid paths are coupled, the joint portion including a primary side connecting portion and a secondary side connecting portion. The primary side connecting portion has a plurality of primary fluid connecting portions to which a plurality of primary side fluid paths are connected. The secondary side connecting portion has a plurality of secondary fluid connecting portions to which a plurality of secondary side fluid paths are connected. Each primary fluid connecting portion is in correspondence with each secondary fluid connecting portion. One of the primary side connecting portion and the secondary side connecting portion is provided integrally. In the remaining one of the primary side connecting portion and the secondary side connecting portion, at least one of the fluid connecting portions is separated from the remaining fluid connecting portions.
In another aspect of the invention, there is provided a fluid coupling unit for coupling a plurality of primary set of fluid paths with a secondary set of fluid paths. The coupling unit includes the above described primary side connecting portion and secondary side connecting portion.